Category Archives: Tech Talk

Technical articles and discussions

Overboost protection and why it’s important

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At Stratified we have recently launched a product called the Guardian Angel which is an overboost protection device for any gasoline fueled turbocharged vehicle.

We get a lot of questions about what such a device does and how it is better than the fuel/ignition cut that is available in most ECUs – so I thought I’d highlight how such a device can be effectively used.

The first thing to remember is that this device is DECOUPLED from the ECU as well as the boost control (both mechanical and electronic) system installed in the car. This makes it a true safety net should something happen.

For example, if a wastegate line pops off, the control system may reduce wastegate duty cycle, may initiate fuel cut, or may do both. However these responses often have delays built into them and do not IMMEDIATELY release boost pressure at the manifold which is what the Guardian Angel does. Whether your wastegate is not working, lines pop off, or you’re playing with the car’s tune and miss a number, the Guardian Angel will always be watching over the vehicle’s boost and preventing a catastrophic condition which often leads to a blown motor or bent rods. The rods below were bent from a 30psi boost spike on a Mazda DISI motor. The ECU just couldn’t react quickly enough to prevent the damage.

We’re not all expert tuners and most importantly we all make mistakes (even the pros) with the installation of parts and tunes. Parts fail all the time – at my most recent dyno day we had a wastegate line pop off that caused a 30psi+ spike – not something healthy for the motor. The last thing we watch at a track day is the boost gauge and this is what the Guardian Angel is constantly doing. It takes the worry out of driving the car in all conditions, installing new parts, and modifying tunes.

The Guardian Angel is easy to install and it works with any ECU or turbo configuration as long as the car is equipped with a push type/piston or diaphragm bypass or blowoff valve. So you can take this from a Mazda to a Honda to a Toyota and it will work the same way. If the device is triggered, you get a visual indicating (via the LED) and the overboost protection is a very gentle one. The ECU can only cut fuel/spark which is very hard on the motor and drivetrain. The Guardian Angel reduces boost but still allows you to keep your foot in it should you be in the middle of a pass for example. Last thing you want is to lose all power with incoming traffic. The Guardian Angel gives you the option to investigate the overboost condition when it is safe. See it in action in the videos below.

As an additional feature, we offer a external trigger for the Guardian Angel. Water/Methanol injection users that have failsafes try and reduce boost using the wastegate if the system fails or tank runs dry. This can be slow and if the wastegate fails it will be ineffective. Instead, you can attach your external trigger wire to the Guardian Angel from the WMI controller or any other ECU.

There have been a few independent review and install articles for the Guardian Angel and these are posted below. Remember that this device is universal to all turbocharged gasoline engines. If you have any questions, please Contact Us.

Guardian Angel Install and Review

Guardian Angel Install

Happy and safe boosting!

The Stratified Team

Knock Retard (KR) Explained

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Knock Detection and mitigation is a very important aspect of the control system of modern vehicles. The availability of very fast ECUs and wideband knock sensors makes it possible for the ECU to adapt the ignition timing to different fuel qualities, temperatures, boost pressures etc. to prevent damage to the engine and achieve maximum performance.

The Mazdaspeed / Mazda MPS vehicles make use of a good knock detection system that is a very good tool used for tuning as well as for maintaining safe operation of the vehicle in variable conditions.

A lot of people datalog the KR (Knock Retard) parameter and have questions regarding what it is really telling them about how their car is running and this is not just Mazdaspeed specific. Essentially the KR value is the amount of timing in degrees that the ECU is pulling from the base map once the knock sensor has picked up noise that it has interpreted as knock. Often, the interpreted knock is very much real while other times it may be something else. I want to clarify several nuances which may spike KR that are NOT caused by detonation and the timing curve.

1. Spool up KR. Here you will see a bit of KR (anything under 1.0 I just take as a “we’ve reached the efficient point” sign). This is common and should not to worry you as long as it dies down like it does here and does not exceed 2.0. Remember the ECU drops KR in steps over a certain period of time and you can see this here and in all logs. If the KR is dropping it means no more knock is detected and the ECU is returning the timing to the base table. Why is there KR in this log? Look at the BATs (Boosted Air Temperature) – they are fairly high just as the boost pressure is climbing.

2. High RPM KR that is a result of mechanical noise/shifting. In the same log  over 6K RPM there is a 0.7-1.0 or so of KR creeping in. This is a sign of mechanical noise but at 0.7 it’s not something to really worry about. Then take a look at the 2.1 KR value before it goes to 0. That is where the driver let off the throttle and the motor moved in the engine bay causing mechanical noise. This is very common in this vehicle – a fast spike just as you shift or right when you let go of the throttle. This is not knock – just the engine moving around in the engine bay – don’t worry about this. You can decrease the sensitivity of the sensor in the high RPM region if the tuning tools allow you. However if it is very high KR (2-3+), you’re either indeed detonating or have a VERY noisy engine (see comment below)

If you see consistent high KR (5+ during WOT runs in this case) and it is not due to timing or during shifting this is caused by other mechanical parts. Anything from a timing chain, to injector seals, to a bent rod. So keep an eye and diagnose this instead of trying to tune around it. Below is what turned out to be KR caused by a bent rod. As you can see it ramps right up to the max 5.95 allowable in this tune at WOT and sits there regardless of timing (which drops into negative numbers).

3. Cold engine KR. When the car is not fully warmed up (even if the temperature gauge tells you it’s fine) you may experience more KR than usual going up in the RPM range or under boost. This is because the engine internals have not reached operating temperature and expansion and are just noisier. Rule of thumb is to drive the car for at least 15 minutes before doing full WOT runs … or to get an oil temperature gauge. Either way, if the car is cold, it’s best to let it warm anyways before really getting on it so this KR serves as a friendly reminder.

Part throttle KR got first generation MazdaSpeed vehicles – some insight

I have recently swapped out the ECU in our shop car for the latest part from Mazda (It’s a gen1 2008.5). This is a different part number from what came in the car and it supersedes all other ECU part numbers for gen1s (there are many). The interesting aspect is that the part throttle and warm-up KR have significantly decreased or completely disappeared with no other changes to the car. Before readings in the 5-6+ KR range were normal as the car warmed up or on the first run of the day as well as at part throttle. Now they are either at 1* KR or below. No hardware changes, no tuning changes, no weather changes, just an ECU swap.

Now how does this play into the whole KR bit? While we have access to some of the knock sensor tuning tables via COBB AccessTuner and VersaTuner, we don’t have access to the filtering algorithm (in the ECU firmware) or hardware. Remember that the knock sensor is a microphone and the ECU filters that signal to interpret knock. Mazda may have updated the hardware or algorithms responsible for this. This is further supported by the fact that the newer cars (gen2) don’t suffer from this “part throttle knock” syndrome nearly as much as the gen1s.

What does this mean? Well it means that the algorithm was perhaps overly sensitive picking up “false knock” initially and not just scaring enthusiasts but losing some efficiency at part throttle since timing was lowered. This can also put to rest some of the fears that people (mainly gen1 owners) have when they see high part throttle KR readings.

Instructional Videos for our Megasquirt Plug and Play Systems

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We realize that if a picture is worth a thousand words – then a video must be … well you get the idea. We plan on augmenting our site with instructional videos that hopefully make it easier to see what the products do, how to set them up etc.

To start off, there is some confusion about what our GENERIC Megasquirt Plug and Play does compared to the vehicle specific ones.

Well, the GENERIC unit is exactly the same as the vehicle specific units – however, the connections have not been made inside to match to the OEM wiring of that particular vehicle.

The first video shows how to go about making those connections and making the GENERIC unit vehicle specific. In this case, we wire it up for a KL Powered Mazda MX-6. This shows you how easy it is to do and how you can save ($140 in this case) by doing this yourself.

A software setup video will follow.

Any questions, please Contact Us as usual

Happy Tuning, The Stratified Team

Understanding Standalone ECUs – Part 1

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At Stratified we believe a well informed tuner and enthusiast will be a happier one and we plan on having a series of technical articles to keep you informed, interested, and even perhaps entertained. This is the first instalment in a discussion regarding standalone ECUs.

So why would you want a standalone ECU anyways?

If you are reading this article, you are probably sitting on the fence or wondering about purchasing a standalone ECU (Engine Control Unit) for your vehicle. Installing such a device in your car can give you access to a wealth of control that will enable you to achieve your goals – or – it can be a big source of frustration.

Making the right choice is simply based on some important information that is often missed when reading forums or even talking to experienced tuners.

First of all, the ECU in your vehicle controls a variety of engine related functions. Its main job is to control the actuators that make the engine run (injectors, coils, idle air control valves, etc.), but it can also have auxiliary functionality (controlling automatic transmissions).

Since the late 1970s and the introduction of fuel injection, ECU development and calibration (or tuning) has been a growing task for manufacturers and the aftermarket alike. The closer we get to today’s date, the more intricate the ECU is, and the more functionality it has. Tighter regulations for emissions, engine efficiency, and performance have resulted in constant improvements and this is in large part due to changes in the electronics driving the motors rather than the basic internal combustion mechanics.

Therefore, the functionality, driveability, performance, and emissions compliance of your vehicle depends on the ECU and its tune (or calibration). Manufacturers spend immense amounts of money, development and testing time to get the most out of your vehicle’s motor and meet emissions requirements – so it’s hard to imagine a private individual being able to do a better job with an aftermarket ECU. So why do so many people want an aftermarket ECU or to change the tune of their cars?

The blanket answer to this is that enthusiasts have different priorities than the original manufacturer for their vehicles. For example, an OEM turbocharged car is set to run 15psi (1 Bar) of boost from the factory. This is done to ensure longevity of the drivetrain. However, if an enthusiast upgrades certain drivetrain components and wishes to run more boost – this requires an ECU re-calibration or the complete replacement of the ECU.

For vehicles manufactured after approximately year 2002, aftermarket tuning companies have taken advantage of the OBDII protocols for vehicle communication and have developed very popular tools for simply flashing the stock ECU. This is an approach that works similarly to a standalone but often lacks on-the-fly tuning and cracking the stock ECU code is often an incomplete job where the tuner doesn’t have access to all the tables or sensor calibration data in the ECU.

In cars that were manufactured between the years of 1985-2000, the accessibility to the stock ECU was not there, or was very slow and cumbersome. If you wanted to run outside of the ECU’s parameters (10-20% above the stock power) you had two main options:

  1. 1. Use some sort of piggyback or mechanical “trick.” AFCs and pressure regulators are often fitted to trick the stock ECU. However, these solutions have a low ceiling and are very crude. Often, the car runs poorly and is sensitive to changes in weather and running conditions. Generally, “tricking” the stock ECU buys you a little bit more headroom above stock – but unfortunately it is not a long-term solution and enthusiasts quickly grow out of these band-aid solutions.

  2. 2. Buy and install a standalone. This requires some expertise, but a standalone is a tool that generally offers an unlimited ceiling when it comes to tuning the motor. They are more expensive than a piggyback, but are adaptable enough to allow for almost limitless tuning possibilities.

There are some caveats however. While having a tool as powerful as a standalone is great, the big question is – when is it necessary?

Here are some indicators that you should consider a standalone for your vehicle:

-Your power goals exceed 10-20% above the stock power of the vehicle

-Your current sensors are reaching caps. For example, the stock airflow sensor is reaching its flow limit

-You have driveability issues such as boost or load cuts

-Your stock actuators are reaching caps. For example, you require more fuel than your stock injectors can provide or your OEM boost control solenoid can’t control your aftermarket wastegate

-Your vehicle is no longer efficient with your current modifications. Gas economy has dropped while operating under similar conditions prior to the modifications

-You wish to recalibrate your vehicle to emphasize power or fuel economy beyond what the OEM manufacturer has done

A standalone when properly tuned will allow:

-Increased reliability of your vehicle for the modifications installed

-Calibration of your vehicle to make the most use out of the modifications installed

-Installation of any injector size to meet greater load demands

-Installation of different load sensors for the power goals desired

-Installation and calibration of aftermarket parts that change engine volumetric efficiency such as pistons, heads, cams, turbochargers etc that are drastically different from the OEM components

-On the fly changes and datalogging for diagnostics and tuning. Standalones offer the best on-the-fly tuning options where the ECU can be calibrated while the motor is turned on. Not even flash solutions can match this versatility. This greatly decreases tuning time

-Improved efficiency and fuel economy

There are lots of benefits to having a standalone installed, but remember that it should be done for the right reasons. In most cars changing the exhaust or adding an intake does not call for a standalone ECU. However, adding a turbocharger to an OEM normally aspirated vehicle often does. Often this is also platform specific and some research is required to see if a particular modification requires a standalone and what tuning solution is best suited for achieving your end goal.

Each platform has their favourite tuning solution – but a good standalone can adapt to almost any platform or motor. Whether it’s a Megasquirt or a Motec, it is important that the ECU is adaptable and that there is plenty of support in the tuning community for the particular ECU. This is one of the biggest advantages of the Megasquirt (aside from cost alone) – it is very versatile and very well supported in many communities.

You should understand that while you are adding this standalone with all its potential, you are also taking into your (or your tuner’s) own hands how the engine operates at all times. It is relatively easy to tune a vehicle at WOT for maximum power, but more time consuming to fine tune low load conditions, tip-in transitions, and weather related compensations.

Furthermore, if Plug and Play (PNP) solutions don’t exist for your platform, the initial wiring and startup can be a challenge in itself. You have to ensure that the standalone will run all the components the OEM unit did in similar ways to the OEM unit. This is why here at Stratified we are focused on reducing the complexity of going standalone by having PNP solutions and offering starting base maps. Getting to the point where the car starts is often one of the most difficult tasks.

In the end, installing and tuning a standalone ECU can be a very rewarding experience, hopefully this article has made the decision of choosing one a little easier. If you have any questions, please feel free to Contact Us.

Happy Tuning,
The Stratified Team